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1.
ScientificWorldJournal ; 2021: 6623609, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33986636

RESUMO

BACKGROUND: Nigella sativa L (NS) is a powerful antioxidant and medicinal plant with many therapeutic applications particularly in traditional medicine for respiratory, gastrointestinal, rheumatic, and inflammatory disorders, as well as cancer. OBJECTIVE: The aim of this study is to extract the active ingredients from the Moroccan Nigella sativa L and determine its antioxidant properties. We hypothesize that the separation of the compounds from Nigella sativa L has either a positive or negative effect on antioxidants. To study this, we explored different methods to simultaneously extract and separate compounds from Nigella sativa L and performed antioxidant tests (ß-carotene and DPPH) for all collected fractions. METHODS: Nigella sativa L was hot-extracted by Soxhlet and mother extracts and was separated using silica column chromatography with adequate eluents. Qualitative phytochemical tests to determine the chemical families in Nigella sativa L seeds were performed on the fractions. They were also identified and characterized by GC-MS and HPLC-DAD. Then, antioxidant activity was examined by ß-carotene bleaching and DPPH radical scavenger tests. Results and Conclusion. The mother extract hexane FH generated eight different fractions (SH1-8) and the acetone extract FA generated 11 fractions (SA1-11). The FH fractions had a high percentage of fatty acids, and the FA fractions had some interesting polyphenols derivative compounds. Phytochemical screening revealed secondary metabolites such as polyphenols flavonoids, alkaloids, steroids, terpenes coumarins, tannins, and saponins. We found that only two solvents (hexane, acetone) of different polarities could easily extract and simultaneously separate the components of Nigella sativa L. The antioxidant fractions that we collected had close activity to reference compounds but were more active than the corresponding mother extracts. Moreover, several IC50 values of fractions from acetone extract were better than those from hexane. Therefore, the antioxidant activity of Nigella sativa L is more attributed to flavonoids and polyphenols than fatty acids. In summary, the separation of hexane extract presents a more pronounced positive effect for antioxidant tests than acetone extract.


Assuntos
Antioxidantes/isolamento & purificação , Flavonoides/isolamento & purificação , Extração Líquido-Líquido/métodos , Nigella sativa/química , Compostos Fitoquímicos/isolamento & purificação , Polifenóis/isolamento & purificação , Sementes/química , Acetona/química , Alcaloides/química , Alcaloides/classificação , Alcaloides/isolamento & purificação , Antioxidantes/química , Antioxidantes/classificação , Compostos de Bifenilo/antagonistas & inibidores , Cromatografia Líquida de Alta Pressão , Cumarínicos/química , Cumarínicos/classificação , Cumarínicos/isolamento & purificação , Flavonoides/química , Flavonoides/classificação , Hexanos/química , Humanos , Marrocos , Compostos Fitoquímicos/química , Compostos Fitoquímicos/classificação , Picratos/antagonistas & inibidores , Extratos Vegetais/química , Plantas Medicinais , Polifenóis/química , Polifenóis/classificação , Saponinas/química , Saponinas/classificação , Saponinas/isolamento & purificação , Solventes/química , Esteroides/química , Esteroides/classificação , Esteroides/isolamento & purificação , Taninos/química , Taninos/classificação , Taninos/isolamento & purificação , Terpenos/química , Terpenos/classificação , Terpenos/isolamento & purificação , beta Caroteno/agonistas
2.
Curr Microbiol ; 77(8): 1419-1428, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32189050

RESUMO

Acinetobacter baumannii is an emerging opportunistic pathogen that primarily infects critically ill patients in nosocomial settings and there is a need for identifying new alternative therapeutic agents against these organisms. Ceragenins are non-peptide, membrane-active agents that mimic the antimicrobial properties of antimicrobial peptides (AMPs) and affect the membrane permeability of microorganisms. The in vitro activities of CSA-8, CSA-13, CSA-44, CSA-131, CSA-138 either alone or in combination with colistin (sulphate) were determined against 25 carbapenem-resistant A. baumannii strains. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of selected ceragenins and colistin against these isolates were measured by in vitro microbroth dilution techniques. Checkerboard techniques and time-kill assays were performed to determine the activities of combinations. The MIC50 values (mg/L) of CSA-8, CSA-13, CSA-44, CSA-131, CSA-138 and colistin were 32, 4, 8, 2, 4 and 0.5, respectively. The MIC90 (mg/L) of CSA-8, CSA-13, CSA-44, CSA-131, CSA-138 and colistin were 128, 8, 16, 8, 16 and 16, respectively. At 6 h, 1×MIC and 2×MIC of CSA-13 were bactericidal. CSA-13 + colistin combination displayed synergistic interaction. Antagonism between antimicrobials was not observed. According to the results, CSA-13 and CSA-131 can be good alternatives for infections caused by carbapenem-resistant A. baumannii.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Viabilidade Microbiana/efeitos dos fármacos , Esteroides/farmacologia , Colistina/farmacologia , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana , Esteroides/classificação
3.
Molecules ; 19(9): 14637-48, 2014 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-25230120

RESUMO

A new natural product, a 3,9-(1,2,3-trioxocine)-type steroid, named rauianodoxy (6), was isolated from Rauia nodosa, together with five steroids: sistostenone (1), stigmastenone (2), sitosterol (3), stigmasterol (4) and ergosterol peroxide (5), one coumarin, O-geranylosthenol (7), and three alkaloids, N-methylflindersine (8), zantobungeanine (9) and veprissine (10). Compounds 5-8 were isolated for the first time in the genus Rauia. These compounds were characterized on the basis of their spectral data, mainly one and two-dimensional NMR, and mass spectra, also involving comparison with the literature data. Theoretical studies at the DFT level reveal structural parameters for the 1,2,3-trioxole bridge compatible with known structures containing a similar group.


Assuntos
Alcaloides/química , Cumarínicos/química , Folhas de Planta/química , Esteroides/química , Triterpenos/química , Alcaloides/isolamento & purificação , Cumarínicos/classificação , Cumarínicos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Rutaceae/química , Espectrometria de Massas por Ionização por Electrospray , Esteroides/classificação , Esteroides/isolamento & purificação , Estigmasterol/química
4.
Nat Prod Rep ; 30(3): 429-54, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23377502

RESUMO

Saponins are an important class of plant natural products that consist of a triterpenoid or steroidal skeleton that is glycosylated by varying numbers of sugar units attached at different positions. Steroidal saponins are usually divided into two broad structural classes, namely spirostanol and furostanol saponins. A third, previously unrecognized structural class of plant saponins, the open-chain steroidal saponins, is introduced in this review; these possess an acyclic sidechain in place of the heterocyclic ring/s present in spirostanols and furostanols. Open-chain steroidal saponins are numerous and structurally diverse, with over 150 unique representatives reported from terrestrial plants. Despite this, they have to date been largely overlooked in reviews of plant natural products. This review catalogs the structural diversity of open-chain steroidal saponins isolated from terrestrial plants and discusses aspects of their structure elucidation, biological activities, biosynthesis, and distribution in the plant kingdom. It is intended that this review will provide a point of reference for those working with open-chain steroidal saponins and result in their recognition and inclusion in future reviews of plant saponins.


Assuntos
Plantas Medicinais/química , Saponinas , Esteroides , Estrutura Molecular , Saponinas/química , Saponinas/classificação , Saponinas/farmacologia , Esteroides/química , Esteroides/classificação , Esteroides/farmacologia
5.
Phytochemistry ; 213: 113731, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37245687

RESUMO

The genus Polygonatum Mill. belongs to the Liliaceae family, which is widely distributed all over the world. Modern studies have found that Polygonatum plants are very rich in chemical compounds such as saponins, polysaccharides and flavonoids. Steroidal saponins are the most commonly studied saponins in the genus Polygonatum and a total of 156 compounds have been isolated from 10 species of the genus. These molecules possess antitumor, immunoregulatory, anti-inflammatory, antibacterial, antiviral, hypoglycemic, lipid-lowering and anti-osteoporotic activities. In this review, we summarize recent advances in studies of the chemical constituents of steroidal saponins from Polygonatum, including their structural characteristics, possible biosynthetic pathways and pharmacological effects. Then, the relationship between the structure and some physiological activities is considered. This review aims to provide reference for further exploitation and utilization of the genus Polygonatum.


Assuntos
Vias Biossintéticas , Polygonatum , Saponinas , Esteroides , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Antivirais/farmacologia , Hipoglicemiantes/farmacologia , Polygonatum/química , Polygonatum/metabolismo , Saponinas/biossíntese , Saponinas/química , Saponinas/classificação , Saponinas/isolamento & purificação , Saponinas/farmacologia , Esteroides/biossíntese , Esteroides/química , Esteroides/classificação , Esteroides/isolamento & purificação , Esteroides/farmacologia , Relação Estrutura-Atividade , Humanos , Animais
6.
Fed Regist ; 77(146): 44456-62, 2012 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-22844688

RESUMO

With the issuance of this Final Rule, the Administrator of the DEA classifies the following two steroids as "anabolic steroids'' under the Controlled Substances Act (CSA): prostanozol (17[beta]-hydroxy-5[alpha]-androstano[3,2-c]pyrazole) and methasterone (2[alpha],17[alpha]-dimethyl-5[alpha]-androstan-17[beta]-ol-3-one). These steroids and their salts, esters, and ethers are Schedule III controlled substances subject to the regulatory control provisions of the CSA.


Assuntos
Anabolizantes/classificação , Androstanóis/classificação , Controle de Medicamentos e Entorpecentes/legislação & jurisprudência , Esteroides/classificação , Rotulagem de Medicamentos/legislação & jurisprudência , Embalagem de Medicamentos/legislação & jurisprudência , Humanos , Estados Unidos
7.
Eur J Pharmacol ; 914: 174579, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34678244

RESUMO

BACKGROUND: Emerging reports have shown the benefits of steroids in hospitalized COVID-19 patients as life-saving drugs. However, the use of steroids in COVID-19 patients is confusing among many physicians. AIM: The aim of the current study was to find out the exact association of steroids in the deaths of COVID-19 patients. METHODS: The relevant studies were searched in PubMed, Google scholar, and Clinical trials registries till May 25, 2021 and sorted out based on inclusion and exclusion criteria. The quality of studies was assessed using a standard scale. The pooled odds ratio was calculated with a 95% confidence interval. The sensitivity and sub-group analyses were also done. The publication bias was assessed qualitatively. The Rev Man 5 was used for all analyses with a random-effect model. RESULTS: The quantitative analysis was done with 9922 patients (6265-male and 3657-females) from 21 relevant studies. The pooled estimate results i.e. 0.52 [0.34, 0.80] have shown a significant reduction in deaths of COVID-19 patients in the steroidal group as compared to the non-steroidal group. The sensitivity analyses did not alter our conclusions. In subgroup analysis, methylprednisolone has shown a significant reduction in deaths of COVID-19 patients as compared to the non-steroidal group, however, more clinical evidence is required for dexamethasone and hydrocortisone. CONCLUSION: The use of steroids in hospitalized COVID-19 patients is useful to reduce deaths.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Metilprednisolona/uso terapêutico , COVID-19/mortalidade , Humanos , Mortalidade , SARS-CoV-2 , Esteroides/classificação , Esteroides/uso terapêutico
8.
Phytochem Anal ; 22(2): 166-71, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21046684

RESUMO

INTRODUCTION: Steroidal saponins are the main active constituents in Ophiopogon japonicus Ker-Gawler (Liliaceae). However, because of their high polarity, non-chromophores and low content in plants, steroidal saponins are difficult to be isolated from O. japonicus by conventional phytochemical methods. OBJECTIVE: To develop a sensitive and rapid approach towards the structural analysis of steroidal saponins using HPLC/ESI-MS(n). METHODOLOGY: The fragmentation behaviors of six known steroidal saponins in negative ESI-MS(n) were used to deduce their mass spectral fragmentation mechanisms. By using HPLC/ESI-MS(n) , the important structural information on aglycone types, sugar types and saccharide sequences can be obtained. RESULTS: According to the HPLC retention behaviour, the molecular structural characteristics provided by multistage mass spectrometry spectra and the literature, a total of 8 steroidal saponins were tentatively identified or characterized in O. japonicus rapidly. CONCLUSION: This work has shown that HPLC-ESI-MS(n) may be used as an effective and rapid method for the characterization and identification of steroidal saponins from O. japonicus.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/química , Ophiopogon/química , Saponinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , China , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/classificação , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/química , Saponinas/classificação , Saponinas/isolamento & purificação , Esteroides/química , Esteroides/classificação , Esteroides/isolamento & purificação
10.
JAMA Netw Open ; 3(9): e2016209, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32990741

RESUMO

Importance: Most patients with primary aldosteronism, a major cause of secondary hypertension, are not identified or appropriately treated because of difficulties in diagnosis and subtype classification. Applications of artificial intelligence combined with mass spectrometry-based steroid profiling could address this problem. Objective: To assess whether plasma steroid profiling combined with machine learning might facilitate diagnosis and treatment stratification of primary aldosteronism, particularly for patients with unilateral adenomas due to pathogenic KCNJ5 sequence variants. Design, Setting, and Participants: This diagnostic study was conducted at multiple tertiary care referral centers. Steroid profiles were measured from June 2013 to March 2017 in 462 patients tested for primary aldosteronism and 201 patients with hypertension. Data analyses were performed from September 2018 to August 2019. Main Outcomes and Measures: The aldosterone to renin ratio and saline infusion tests were used to diagnose primary aldosteronism. Subtyping was done by adrenal venous sampling and follow-up of patients who underwent adrenalectomy. Statistical tests and machine-learning algorithms were applied to plasma steroid profiles. Areas under receiver operating characteristic curves, sensitivity, specificity, and other diagnostic performance measures were calculated. Results: Primary aldosteronism was confirmed in 273 patients (165 men [60%]; mean [SD] age, 51 [10] years), including 134 with bilateral disease and 139 with unilateral adenomas (58 with and 81 without somatic KCNJ5 sequence variants). Plasma steroid profiles varied according to disease subtype and were particularly distinctive in patients with adenomas due to KCNJ5 variants, who showed better rates of biochemical cure after adrenalectomy than other patients. Among patients tested for primary aldosteronism, a selection of 8 steroids in combination with the aldosterone to renin ratio showed improved effectiveness for diagnosis over either strategy alone. In contrast, the steroid profile alone showed superior performance over the aldosterone to renin ratio for identifying unilateral disease, particularly adenomas due to KCNJ5 variants. Among 632 patients included in the analysis, machine learning-designed combinatorial marker profiles of 7 steroids alone both predicted primary aldosteronism in 1 step and subtyped patients with unilateral adenomas due to KCNJ5 variants at diagnostic sensitivities of 69% (95% CI, 68%-71%) and 85% (95% CI, 81%-88%), respectively, and at specificities of 94% (95% CI, 93%-94%) and 97% (95% CI, 97%-98%), respectively. The validation series yielded comparable diagnostic performance. Conclusions and Relevance: Machine learning-designed combinatorial plasma steroid profiles may facilitate both screening for primary aldosteronism and identification of patients with unilateral adenomas due to pathogenic KCNJ5 variants, who are most likely to show benefit from surgical intervention.


Assuntos
Hiperaldosteronismo/tratamento farmacológico , Aprendizado de Máquina/tendências , Esteroides/classificação , Adulto , Feminino , Humanos , Hiperaldosteronismo/fisiopatologia , Masculino , Pessoa de Meia-Idade , Polônia , Esteroides/uso terapêutico
11.
J Am Med Inform Assoc ; 16(1): 116-31, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18952946

RESUMO

OBJECTIVE: Chemical concepts assigned multiple "Chemical Viewed Structurally" semantic types (STs) in the Unified Medical Language System (UMLS) are subject to ambiguous interpretation. The multiple assignments may denote the fact that a specific represented chemical (combination) is a conjugate, derived via a chemical reaction of chemicals of the different types, or a complex, composed of a mixture of such chemicals. The previously introduced Refined Semantic Network (RSN) is modified to properly model these varied multi-typed chemical combinations. DESIGN: The RSN was previously introduced as an enhanced abstraction of the UMLS's concepts. It features new types, called intersection semantic types (ISTs), each of which explicitly captures a unique combination of ST assignments in one abstract unit. The ambiguous ISTs of different "Chemical Viewed Structurally" ISTs of the RSN are replaced with two varieties of new types, called conjugate types and complex types, which explicitly denote the nature of the chemical interactions. Additional semantic relationships help further refine that new portion of the RSN rooted at the ST "Chemical Viewed Structurally." MEASUREMENTS: The number of new conjugate and complex types and the amount of changes to the type assignment of chemical concepts are presented. RESULTS: The modified RSN, consisting of 35 types and featuring 22 new conjugate and complex types, is presented. A total of 800 (about 98%) chemical concepts representing multi-typed chemical combinations from "Chemical Viewed Structurally" STs are uniquely assigned one of the new types. An additional benefit is the identification of a number of illegal ISTs and ST assignment errors, some of which are direct violations of exclusion rules defined by the UMLS Semantic Network. CONCLUSION: The modified RSN provides an enhanced abstract view of the UMLS's chemical content. Its array of conjugate and complex types provides a more accurate model of the variety of combinations involving chemicals viewed structurally. This framework will help streamline the process of type assignments for such chemical concepts and improve user orientation to the richness of the chemical content of the UMLS.


Assuntos
Compostos Orgânicos/classificação , Unified Medical Language System , Aminoácidos/química , Aminoácidos/classificação , Árvores de Decisões , Estrutura Molecular , Compostos Orgânicos/química , Peptídeos/química , Peptídeos/classificação , Proteínas/química , Proteínas/classificação , Semântica , Esteroides/química , Esteroides/classificação
12.
Fed Regist ; 74(232): 63603-10, 2009 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-20169675

RESUMO

With the issuance of this final rule, the Deputy Administrator of the Drug Enforcement Administration (DEA) classifies the following three steroids as "anabolic steroids" under the Controlled Substances Act (CSA): Boldione, desoxymethyltestosterone, and 19-nor-4,9(10)-androstadienedione. These steroids and their salts, esters, and ethers are schedule III controlled substances subject to the regulatory control provisions of the CSA.


Assuntos
Anabolizantes/classificação , Androstadienos/classificação , Controle de Medicamentos e Entorpecentes/legislação & jurisprudência , Metiltestosterona/classificação , Esteroides/classificação , Testosterona/classificação , Humanos , Legislação de Medicamentos , Testosterona/análise , Estados Unidos
13.
J Comput Chem ; 29(3): 317-33, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17639502

RESUMO

The great cost associated with the development of new anabolic-androgenic steroid (AASs) makes necessary the development of computational methods that shorten the drug discovery pipeline. Toward this end, quantum, and physicochemical molecular descriptors, plus linear discriminant analysis (LDA) were used to analyze the anabolic/androgenic activity of structurally diverse steroids and to discover novel AASs, as well as also to give a structural interpretation of their anabolic-androgenic ratio (AAR). The obtained models are able to correctly classify 91.67% (86.27%) of the AASs in the training (test) sets, respectively. The results of predictions on the 10% full-out cross-validation test also evidence the robustness of the obtained model. Moreover, these classification functions are applied to an "in house" library of chemicals, to find novel AASs. Two new AASs are synthesized and tested for in vivo activity. Although both AASs are less active than some commercially AASs, this result leaves a door open to a virtual variational study of the structure of the two compounds, to improve their biological activity. The LDA-assisted QSAR models presented here, could significantly reduce the number of synthesized and tested AASs, as well as could increase the chance of finding new chemical entities with higher AAR.


Assuntos
Anabolizantes/química , Anabolizantes/farmacologia , Reconhecimento Automatizado de Padrão/métodos , Relação Quantitativa Estrutura-Atividade , Esteroides/química , Esteroides/farmacologia , Algoritmos , Anabolizantes/classificação , Fenômenos Químicos , Físico-Química , Análise por Conglomerados , Simulação por Computador , Análise Discriminante , Ligantes , Estrutura Molecular , Teoria Quântica , Reprodutibilidade dos Testes , Esteroides/classificação
14.
Neuropsychopharmacology ; 31(6): 1249-63, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16319920

RESUMO

Evidence suggests that neuroactive steroids may be candidate modulators of schizophrenia pathophysiology and therapeutics. We therefore investigated neuroactive steroid levels in post-mortem brain tissue from subjects with schizophrenia, bipolar disorder, nonpsychotic depression, and control subjects to determine if neuroactive steroids are altered in these disorders. Posterior cingulate and parietal cortex tissue from the Stanley Foundation Neuropathology Consortium collection was analyzed for neuroactive steroids by negative ion chemical ionization gas chromatography/mass spectrometry preceded by high-performance liquid chromatography. Subjects with schizophrenia, bipolar disorder, nonpsychotic depression, and control subjects were group matched for age, sex, ethnicity, brain pH, and post-mortem interval (n = 14-15 per group, 59-60 subjects total). Statistical analyses were performed by ANOVA with post-hoc Dunnett tests on log transformed neuroactive steroid levels. Pregnenolone and allopregnanolone were present in human post-mortem brain tissue at considerably higher concentrations than typically observed in serum or plasma. Pregnenolone and dehydroepiandrosterone levels were higher in subjects with schizophrenia and bipolar disorder compared to control subjects in both posterior cingulate and parietal cortex. Allopregnanolone levels tended to be decreased in parietal cortex in subjects with schizophrenia compared to control subjects. Neuroactive steroids are present in human post-mortem brain tissue at physiologically relevant concentrations and altered in subjects with schizophrenia and bipolar disorder. A number of neuroactive steroids act at inhibitory GABA(A) and excitatory NMDA receptors and demonstrate neuroprotective and neurotrophic effects. Neuroactive steroids may therefore be candidate modulators of the pathophysiology of schizophrenia and bipolar disorder, and relevant to the treatment of these disorders.


Assuntos
Transtorno Bipolar/metabolismo , Encéfalo/metabolismo , Esquizofrenia/metabolismo , Esteroides/metabolismo , Análise de Variância , Transtorno Bipolar/patologia , Encéfalo/patologia , Estudos de Casos e Controles , Cromatografia Líquida de Alta Pressão/métodos , Depressão/metabolismo , Depressão/patologia , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Masculino , Modelos Moleculares , Mudanças Depois da Morte , Esquizofrenia/patologia , Fatores Sexuais , Esteroides/classificação
16.
J Control Release ; 107(1): 174-82, 2005 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-16126297

RESUMO

Recently, cationic steroids have been developed that display broad-spectrum antibacterial activity. These compounds, characterized by the presence of several amino groups, present a facially amphiphilic morphology. Formulations containing such steroids were tested for their ability to facilitate the uptake of a reporter plasmid into various cell lines. The results show that, when associated with the naturally occurring zwitterionic lipid dioleoyl-phosphatidylethanolamine (DOPE), cationic steroid antibiotics allow for transfection levels comparable to those obtained with DOTAP. The activity of the amphiphilic mixture was nearly unaffected by bafilomycin A1 and chloroquine treatment, suggesting a mechanism that is independent of the acidification process associated with endocytosis. Collectively, our results show that DNA delivery agents possessing strong antibacterial properties can be obtained by conjugating amino groups to a steroid nucleus.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , DNA/genética , Técnicas de Transferência de Genes , Esteroides , Antibacterianos/química , Antibacterianos/farmacocinética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Peptídeos Catiônicos Antimicrobianos/farmacocinética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular , Linhagem Celular Transformada , Linhagem Celular Tumoral , DNA/metabolismo , Ácidos Graxos Monoinsaturados/química , Genes Reporter , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Luciferases/metabolismo , Fosfatidiletanolaminas/química , Plasmídeos , Compostos de Amônio Quaternário/química , Esteroides/química , Esteroides/classificação , Esteroides/farmacologia , Transfecção
17.
Neurosci Lett ; 384(1-2): 156-61, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15927368

RESUMO

Dehydroepiandrosterone (DHEA), pregnenolone (P) and their sulfate derivatives are neuroactive neurosteroids synthesized endogenously in the brain and in steroidogenic organs and influence or are influenced by a variety of physiological processes. Since parturition is followed by a rapid drop in estrogen levels in serum and brain it may be hypothesized that the drastic drop in the brain exposure to estrogens may cause a disturbance in the neurosteroid-to-neurosteroid-sulfate equilibrium with clinical relevance. In order to develop a rat animal model for human postpartum rapid estrogen decline conditions, the present study investigated effects of sudden withdrawal of hyperphysiological estrogens levels on levels of DHEA, DHEAS, P and PS in peripheral blood and brain tissue as well as cortical sulfatase activity. Twenty-four 3-month-old female rats were ovarectomized followed by either no estrogen, high levels of estrogen alone, or followed by sudden withdrawal after high-administered estrogen levels. Results indicated elevated brain cortical DHEA-S and reduced cortical sulfatase in ovarectomized rats following sudden estrogen withdrawal. No significant alterations in DHEA, P or PS were noted. Study observations suggest the marked influence estrogen withdrawal states may have on cortical DHEA-S levels in particular, the precise mechanism of which remains unknown but which may be related to the paralleled decrease in sulfatase activity. This DHEA-S increase may lead to attenuated GABAergic tone and may be relevant to post-natal behavioral disturbances (e.g. depression, anxiety).


Assuntos
Encéfalo/metabolismo , Estradiol/efeitos adversos , Ovariectomia , Esteroides/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Química Encefálica , Estradiol/administração & dosagem , Feminino , Radioimunoensaio/métodos , Ratos , Ratos Sprague-Dawley , Esteroides/classificação , Síndrome de Abstinência a Substâncias/etiologia , Sulfatases/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-15694225

RESUMO

The term "neurosteroid" (NS) was introduced by Baulieu in 1981 to name a steroid hormone, dehydroepiandrosterone sulfate (DHEAS), that was found at high levels in the brain long after gonadectomy and adrenalectomy, and shown later to be synthetized by the brain. Later, androstenedione, pregnenolone and their sulfates and lipid derivatives as well as tetrahydrometabolites of progesterone (P) and deoxycorticosterone (DOC) were identified as neurosteroids. The term "neuroactive steroid" (NAS) refers to steroids which, independent of their origin, are capable of modifying neural activities. NASs bind and modulate different types of membrane receptors. The GABA and sigma receptor complexes have been the most extensively studied, while glycine-activated chloride channels, nicotinic acetylcholine receptors, voltage-activated calcium channels, although less explored, are also modulated by NASs. Within the glutamate receptor family, N-methyl-d-aspartate (NMDA) receptors, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and kainate receptors have also been demonstrated to be a target for steroid modulation. Besides their membrane effects, once inside the neuron oxidation of Ring A reduced pregnanes, THP and THDOC, bind to the progesterone intracellular receptor and regulate gene expression through this path. The involvement of NASs on depression syndromes, anxiety disorders, stress responses to different stress stimuli, memory processes and related phenomena such as long-term potentiation are reviewed and critically evaluated. The importance of context for the interpretation of behavioral effects of hormones as well as for hormonal levels in body fluids is emphasized. Some suggestions for further research are given.


Assuntos
Encéfalo/metabolismo , Neurônios/efeitos dos fármacos , Psicopatologia , Esteroides/farmacologia , Animais , Ansiedade/tratamento farmacológico , Ansiedade/metabolismo , Química Encefálica , Depressão/tratamento farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Humanos , Neurônios/citologia , Neurônios/fisiologia , Receptores de Glutamato/classificação , Receptores de Glutamato/efeitos dos fármacos , Receptores de Glutamato/fisiologia , Esteroides/química , Esteroides/classificação , Esteroides/uso terapêutico , Estresse Fisiológico/metabolismo , Estresse Fisiológico/fisiopatologia
20.
Microbes Infect ; 5(1): 13-7, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12593968

RESUMO

Helicobacter pylori has a particular affinity to cholesterol. It is not known, however, whether other steroidal substances are bound as well. In order to characterize the specificity and nature of the H. pylori-steroid interaction, the affinity of H. pylori to cholesterol and several steroidal hormones was investigated. Seven strains of H. pylori (five reference strains, two wild strains) and one strain each of Staphylococcus epidermidis and Escherichia coli were cultured on a cholesterol-free medium. Cholesterol-free bacteria were incubated with cyclodextrin-mediated cholesterol and several cyclodextrin-mediated steroidal hormones (beta-estradiol, testosterone, progesterone, hydrocortisone, dexamethasone). The steroid contents of the bacteria were determined by gas liquid chromatography. High amounts of cholesterol were detected in all H. pylori strains, whilst steroidal hormones were not found. Neither S. epidermidis nor E. coli showed an appreciable amount of cholesterol in the chromatographic examinations. Bacterial pretreatment with proteinase K diminished cholesterol adsorption of H. pylori. These data indicate a specific affinity of H. pylori to cholesterol. This unique property might serve as a pathogenicity component enabling survival and colonization of H. pylori in the gastric environment.


Assuntos
Colesterol/metabolismo , Helicobacter pylori/metabolismo , Esteroides/metabolismo , Adsorção , Cromatografia Gasosa/métodos , Endopeptidase K/metabolismo , Ácidos Graxos/análise , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Humanos , Sensibilidade e Especificidade , Esteroides/classificação
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